Defining 'artificial intelligence' for regulation

In the course of the most recent wave of expectation and hype about "artificial intelligence" (AI) -- let's say the last 10 years -- there have been repeated attempts to define what it is. Serious documents such as from academics, governments, or professional bodies typically say that there is no agreed definition and then propose their own or fall back on a well-known one (for example the UK Government used the phrasing: "AI can be defined as the use of digital technology to create systems capable of performing tasks commonly thought to require intelligence"). Popular articles tend not to agonise about it, but use the term to imply something technically advanced or futuristic. But now that governments are crafting laws referring to AI (e.g. the EU's AI Act and the UK National Security and Investment Act 2021) it is beginning to matter a lot. The scope of a law should include neither too much nor too little; be clear which cases fall within it and which do not; be understandable by anyone using it; anyone should be able to easily determine whether a case falls under it, and it should not need continual updating. Consequently, the debate on the scope of the EU AI Act (ongoing at the time of writing) is crucial to the impact of the eventual regulation.